Disc brake having an electromotively actuated adjusting system

ABSTRACT

The invention relates to a disc brake, particularly for utility vehicles, comprising a brake caliper that overlaps a brake disc, a tensioning device for tensioning brake pads, and an adjusting system for compensating for wear to the brake pads and/or brake disc. Said adjusting system has at least one electric motor that serves as a drive. The disc brake is characterized in that the at least one electric motor is mounted on the brake caliper in a manner that permits it to be accessed from the exterior.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a disc brake and, in particular, to a discbrake for utility vehicles.

Disc brakes with an electromotively actuated adjusting system are knownper se; thus, for example, from German Patent Document DE 197 56 519 A1.A center arrangement of the adjusting drive between the rotating andadjusting screws is also known, for example, from German Patent DocumentDE 37 16 202 A1 or International Patent Document WO99/05428.

The idea of using an electric adjusting motor for driving the adjustingdevice of the disc brake has been successful per se. However, it isdesirable to create a disc brake in the case of which, on the one hand,the electric motor is particularly easily accessible in order to ensurean uncomplicated exchange of the electric motor. Furthermore, theelectric motor should also be arranged at a site of the disc brake whichis relatively insensitive to temperatures, so that it will not besubjected to an excessive heat development during braking.

The invention has the object of solving the above-mentioned problems.

The invention achieves this task by providing a disc brake, particularlyfor utility vehicles, having a caliper which extends over a brake disc,a brake application device for the application of the disc brake, aswell as an adjusting system for compensating brake pad wear and/or brakedisc wear. The adjusting system has at least one electric motor as adrive, wherein the at least one electric motor is arranged on thecaliper such that it is accessible from an exterior of the caliper.

In contrast to the state of the art, at least one or more electricmotors are arranged on the caliper such that they are accessible fromthe outside. This area of the disc brake is subjected to a clearly lowerheat development during braking than the caliper interior where heat istransmitted to the elements in the interior of the caliper by way of thebrake pads.

Furthermore, a particularly easy exchangeability of the at least oneelectric motor can be implemented in an exterior area of the caliper orat the caliper exterior.

The at least one electric motor is preferably coupled by way of adriving connection with at least one adjusting device within thecaliper, in which case the driving connection can be constructed in acost-effective manner as a shaft.

If the at least one electric motor is mounted, either completely or insections, in a recess on the exterior side of the caliper, the electricmotor can be protected against weather influences and damage by rocksand the like in a simple manner. This protection can be supplemented bya covering.

If the adjusting system on one or on both sides of the brake disc isconstructed as an adjuster module, which can be preassembled and whichhas the driving connection to the electric motor and a reduction gearconnected behind the electric motor, an adjusting sleeve being attachedto the at least one mounting plate, an easy pre-assembly and finalassembly of the adjusting system can be implemented at low costexpenditures.

The invention is suitable for electromotively or pneumatically actuateddisc brakes, which have a floating caliper, a fixed caliper or a slidingcaliper. One of the adjusting devices, respectively, is preferablyconstructed on both sides of the brake disc.

Additional advantageous further developments of the invention aredescribed and claimed herein.

In the following, preferred embodiments are described in detail by meansof the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of essential elements of a first embodimentof a disc brake according to the invention with a caliper which is onlypartially illustrated;

FIG. 2 is a sectional view of the disc brake of FIG. 1;

FIG. 3 is a top view of the disc brake of FIG. 1, only a portion of thecaliper being shown;

FIG. 4 is a perspective view of the adjusting system of the disc brakeof FIG. 1 with only a portion of the rotary lever being shown;

FIG. 5 is a top view of the adjusting system of FIG. 4;

FIG. 6 is a perspective view of essential elements of another embodimentof a disc brake according to the invention with a caliper which is onlypartially illustrated;

FIG. 7 is a sectional view of the disc brake of FIG. 6;

FIG. 8 is a top view of the disc brake of FIG. 7, with only a portion ofthe caliper being shown;

FIG. 9 is a partially transparent view of another disc brake;

FIG. 10 is another partially sectional and partially perspective view ofthe disc brake of FIG. 6;

FIG. 11 is a perspective view of the adjusting system of the disc brakeof FIG. 6, with a partially illustrated rotary lever;

FIG. 12 is a top view of the adjusting system with the rotary leveraccording to FIG. 11;

FIG. 13 is a schematic diagram of a disc brake;

FIG. 14 is a partial, sectional, top view of a disc brake, which can beequipped with an electric motor of the type shown in FIG. 1; and

FIG. 15 is a view of an adjusting module.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 13 illustrates a preferably pneumatically or electromotivelyoperable disc brake having a caliper 1 which straddles a brake disc 3 inan upper circumferential area of the brake disc.

On both sides of the brake disc 3, brake pads 5, 7 are arranged. Thebrake pads 5, 7 are displaceable in the direction of the brake disc, aswell as away from the brake disc, that is, perpendicularly to the planeof the brake disc 3. The brake pads 5, 7, in a conventional manner,consist of a brake pad carrier 5 a, 7 a and of a pad material 5 b, 7 bapplied thereto.

In FIG. 13, the caliper 1 is fastened at a right lower section 9, whichsection extends in the direction of the axle shaft (not shown here) bymeans of at least one, or preferably more, bolts 11, for example, on anaxle flange 13 of the disc brake.

As an example, the brake disc 3 is constructed here as a sliding disc,which is displaceable by the amount of the working stroke to be overcomeduring braking relative to the brake caliper 1 on the wheel axle. As analternative, or in addition, the caliper 1 may also be constructed in adisplaceable or swivellable manner. In addition, it can be that thecaliper 1 and/or the brake disc 3 are, in each case, constructed to beelastically deformable by a portion of the path of the working stroke.

Since, according to FIG. 13, a relative movement exists between thecaliper and the brake disc, which movement essentially corresponds tothe amount of the working stroke, adjusting devices 15, 17 are providedand necessary on both sides of the brake disc in order to compensate forthe release play or the brake pad wear occurring during braking.

On each side of the brake disc 3, the adjusting devices 15, 17 consistof, for example, in each case at least one or more, preferably two,adjusting sleeves 19, 21. Bolt-type extensions 24 (spindles) of pressurepieces 23, 25 are rotatably arranged in the sleeves 19, 21, so that arelative axial mobility exists between the adjusting sleeves 21, 23 aswell as the pressure pieces 23, 25 (see FIG. 15). Naturally, a reversearrangement is also contemplated, in the case of which the pressurepieces 23, 25 have a sleeve-type extension (not shown here) which can berotated on a bolt (spindle).

The adjusting device 15 illustrated on the right in FIG. 13 is supportedon a rotary lever 27 pertaining, in addition to the adjusting device 15,to the brake application device, which rotary lever 27 can be actuatedin its area at the top in FIG. 13 by a piston rod 29 of a brake cylinder31 and which, in its lower part, for example, by way of ball bearingelements (not shown here) or another bearing, is disposed at thecaliper. The rotary lever 27 is also disposed on its side facing awayfrom the caliper directly, or by way of intermediate elements, such asballs and/or additional intermediate pieces on the adjusting sleeve 19.In contrast, the adjusting sleeve 21 arranged on the side of the brakedisc 1 situated opposite the rotary lever 27 is supported directly atthe caliper interior.

FIG. 14 is a top view of a disc brake of the type shown in FIG. 13, inwhich case two adjusting sleeves 19 a, 19 b (see also FIG. 15) as wellas two pressure pieces 23 a, 23 b, 25 a, 25 b (see also FIGS. 4 and 5)are arranged on both sides of the brake disc, which can be mutuallysynchronized by way of a gear wheel mechanism. This is also illustratedparticularly well in FIG. 15. The adjusting sleeve 19 a illustrated hereis equipped at its outer circumference with a gear wheel 33 a or agear-wheel-type projection, which meshes with a gear wheel 35 a, whichin turn is driven by a gear wheel 37 a, which in turn is rotated by anoutput gear wheel 39 of an electric motor 41. All gear wheels 33 a, 35a, 37 a, 39 are situated in a common plane.

Analogous thereto, the additional adjusting sleeve 19 b (see FIG. 15) isalso provided with a toothing or a gear wheel 33 b (see also FIG. 4) onits outer circumference, which meshes with an additional gear wheel 35b, which in turn is rotated by a gear wheel 37 b, which is also drivenby the output gear wheel 39 of the electric motor 41.

In this case, the gear wheels 37 a, 37 b are applied to mutuallyopposite sides of the output gear wheel 39. All gear wheels 33 to 39 aremounted by means of their axes on a mounting plate 42, which hasrecesses for the axes of the gear wheels as well as for allowing theadjusting sleeves 19 a, 19 b to extend through.

On the side of the mounting plate 42 situated opposite the gear wheels33 to 39, an electric motor 41 is arranged in the center between the twoadjusting sleeves 19, 21. In their area facing away from the gear wheels33, the adjusting sleeves 19 reach through shaped-out sections andopenings of another second mounting plate 43 arranged parallel to thefirst mounting plate 42, which second mounting plate 43 has bores 45 forthe screwed connection at the caliper 1, so that the second mountingplate 43 is also used as a closing plate for an opening 47 of thecaliper 1 facing the brake disc, which opening is illustrated, forexample, in FIG. 1. The caliper 1 is provided with bores 49 whichcorrespond with the bores 45.

The pressure pieces 23, 25 are, in each case, inserted into the secondmounting plate 43, in which case the shaped-out sections 51 in thesecond mounting plate 43 are designed for receiving the ends of thepressure pieces that act upon the brake pads.

According to FIG. 15, a constructively simple adjusting module, whichcan be pre-assembled, is created. This adjusting module can be placed onboth sides of the brake disc 3 in a pre-assembled manner in the caliper,after the rotary lever 27 is mounted in the caliper.

This arrangement is cost-effective and compact. Nevertheless, there is ademand for an alternative housing of the electric motor 41 since, in thearea between the pressure pieces 23, 25, the motor 41 is subjected torelatively high temperatures.

For avoiding this problem, according to FIG. 1, the electric motors 41′are no longer arranged on both sides of the brake disc between the twomounting plates 42, 43. Rather, the electric motors 41′ are arranged onthe caliper such that they are accessible from the outside, and areconnected to the output gear wheel 39 in each case by way of a drivingconnection—here, a shaft 53 lengthened in the axial direction of theaxis of the gear wheel 39. According to FIGS. 1 to 5, the shaft 53, ineach case an extension of the shaft of the gear wheel 39, is guidedperpendicularly through the caliper to the outside. The rotary lever 27also has a bore 55 in order to allow the shaft 53 to extend toward theoutside (see FIGS. 2-5). The caliper, in each case, also hascorresponding bores on both sides of the brake disc which allow for theshaft to extend through (which, however, are not visible in FIG. 1).

On its exterior sides, the caliper 1 can preferably be provided withrecesses 56 (visible in FIG. 2 in the left edge), so that the electricmotor 41′ engages (mounts) in the caliper. The electric motor 41′ itselfmay have a robust covering 57, 58 so that it is securely protectedagainst rough environmental influences.

The important advantage of this arrangement is, on the one hand, theeasy accessibility of the electric motor 41′ and thus the simplepossibility of its exchange. On the other hand, a lower temperatureexists on the exterior sides of the caliper 1 during braking than in thecaliper interior, so that the electric motor 41′, in comparison to thestate of the art, according to the invention is subjected to lessheating during braking.

In the additional embodiments of FIGS. 6 to 12, it is provided that thetwo gear wheels or gear-wheel-type extensions 33 a, 33 b at the outercircumference of the adjusting sleeves 19, 21 in turn mesh, in eachcase, with gear wheels 35 a, 35 b, which, however, are placed on a shaft59. The shaft 59 carries additional gear wheels 61 a, 61 b offsetparallel to the gear wheels 35 a, 35 b. The additional gear wheels 61 a,61 b mesh with worm gears 63, 65 which are mounted on a joint shaft 67,which mutually connects the two worm gears 63, 65.

Here, a diagonal alignment exists on one side of the rotary lever 27such that, relative to the top view of the disc brake, the shaft 67, ineach case, at one adjusting sleeve 19 a is applied once to the lowercircumference of the gear wheel 61 a and, at the other adjusting sleeve19 b, is applied to the upper circumference of the gear wheel 61 b. Onthe opposite side of the brake disc, the engagement of the shaft 67 inthe gear wheels 61 a, 61 b is reversed; that is, relative to the topview of the disc brake, the shaft 67, in each case, at one adjustingsleeve 19 b is applied to the lower circumference of the gear wheel 61 band, at the other adjusting sleeve 19 a, is applied to the uppercircumference of the gear wheel 61 a.

As indicated particularly clearly in FIG. 6, the shaft 67 is, in eachcase, constructed to be so long that, as a result of a shaft lengthening69 of the shaft 67 on both sides of the brake disc 3, in each case adriving connection penetrating the caliper wall to the electric motors41″ is established, which motors 41″ are in turn arranged on the outsideon the caliper.

As indicated particularly clearly in FIG. 9, the electric motor 41″ issituated, for example, in a recess 71 of the caliper, where it is inturn well protected against higher temperatures caused by the brakingand can easily be exchanged. According to FIG. 9, instead of an axialextension 69, a separate drive shaft 70 is provided, which is coupled byway of a gear wheel 72 with the shaft 67.

According to FIGS. 1 to 5, as well as according to FIGS. 6 to 12, one ofthe adjusting devices 15, 17, respectively, is provided on both sides ofthe brake disc 3. The adjusting devices 15, 17 each have an electricmotor (41′ or 41″) respectively arranged on the exterior side of thecaliper 1 relative to the other components of the adjusting devices 15,17 and are connected by way of bores or the like extending through thecaliper with the components of the adjusting devices 15, 17 in thecaliper interior.

Table of Reference Numbers

-   caliper 1-   brake disc 3-   brake pad 5-   brake pad carrier 5 a/5 b-   brake pad 7-   brake pad carrier 7 a/7 b-   section 9-   bolt 11-   axle flange 13-   adjusting device 15-   adjusting device 17-   adjusting sleeve 19-   adjusting sleeve 19 a/19 b-   adjusting sleeve 21-   pressure piece 23-   pressure piece 23 a/23 b-   spindle 24-   pressure piece 25-   pressure piece 25 a/25 b-   rotary lever 27-   piston rod 29-   gear wheel/attachment 33-   gear wheel 35-   gear wheel 37-   gear wheel 39-   electric motor 41/41′/41″-   mounting plate 42-   mounting plate 43-   bore 45-   opening 47-   bore 49-   shaped-out section 51-   shaft 53-   bore 55-   indentation 56-   covering 57-   shaft 59-   gear wheel 61-   gear wheel 61 a/61 b-   worm gear 63-   worm gear 65-   shaft 67-   axial extension 69-   recess 71-   gear wheel 72

1-9 (canceled).
 10. A pneumatically operated disc brake, comprising: acaliper extending over a brake disc; a brake application device having arotary lever, the brake application device displacing brake pads againstthe brake disc; an adjusting system that compensates for at least one ofbrake pad wear and brake disc wear, wherein the adjusting systemincludes at least one electric motor to drive the adjusting system;wherein the at least one electric motor is arranged on the caliper suchthat it is accessible from an exterior of the caliper, the at least oneelectric motor being drivingly connected with components of theadjusting system arranged within the caliper; wherein the drivingconnection includes a shaft that penetrates a wall of the caliper andextends through a bore in the rotary lever of the brake applicationdevice.
 11. The disc brake according to claim 10, wherein for mountingthe at least one electric motor, a recess is provided on an exteriorside of the caliper.
 12. The disc brake according to claim 11, whereinthe electric motor is mounted either completely or partially in therecess.
 13. The disc brake according to claim 10, wherein the at leastone electric motor has a cover.
 14. The disc brake according to claim11, wherein the at least one electric motor has a cover.
 15. The discbrake according to claim 12, wherein the at least one electric motor hasa cover.
 16. The disc brake according to claim 10, wherein the adjustingsystem comprises at least one of pressure pieces and adjusting sleeves,and wherein the shaft has one of a gear wheel and one or more worm gearsmeshing either directly or via additional intermediately connected driveelements with said at least one of the pressure pieces and adjustingsleeves.
 17. The disc brake according claim 10, wherein the adjustingsystem includes two adjusting devices, one adjusting device beingarranged on each side of the brake disc and including at least twopressure pieces that act upon each brake pad; and wherein each adjustingdevice has an associated electric motor, which motor acts upon asynchronization gear coupling rotating movements of the at least twopressure pieces of the adjusting device.
 18. The disc brake according toclaim 10, wherein the adjusting system includes at least one adjustermodule, which module is preassembleable and includes the shaft, areduction gear connected on an output side of the electric motor, and anadjusting sleeve attached to at least one mounting plate.
 19. The discbrake according to claim 10, wherein the disc brake has one of afloating, fixed, and sliding caliper.
 20. A wear compensation adjustingsystem for use with a disc brake having a caliper that extends over abrake disc and a rotary lever brake application device for applying thebrake pads against the brake disc, the wear compensation adjustingsystem comprising: a first electric motor adapted to be arranged on thecaliper so as to be externally accessible; a first wear adjusting deviceadapted to be arranged within the caliper; and a drive connectionextending between the first wear adjusting device within the caliper andthe first electric motor.
 21. The wear compensation adjusting systemaccording to claim 20, wherein the first electric motor is adapted to atleast partially mount into a recess on the caliper.
 22. The wearcompensation adjusting system according to claim 20, wherein the firstelectric motor is adapted to engage completely within a recess on thecaliper.
 23. The wear compensation adjusting system according to claim20, wherein the first electric motor has a protective cover.
 24. Thewear compensation adjusting system according to claim 20, wherein thefirst wear adjusting device includes at least one of an adjusting sleeveand a pressure piece, the drive connection having a geared couplingmeshing either directly or via intermediate drive elements with said atleast one of the adjusting sleeve and the pressure piece.
 25. The wearcompensation adjusting system according to claim 20, further comprisinga second wear adjusting device, said first and second wear adjustingdevices being arrangeable on opposite sides of the brake disc, and eachof the first and second wear adjusting devices including at least twopressure pieces.
 26. The wear compensation adjusting system according toclaim 25, further comprising a second electric motor, the first andsecond electric motors being correspondingly associated with the firstand second wear adjusting devices, each electric motor acting upon asynchronized gear coupling between the at least two pressure pieces ofthe adjusting device.
 27. The wear compensation adjusting systemaccording to claim 20, wherein the first wear adjusting device is apreassembled unit comprising at least a mounting plate, a reduction gearcoupleable with an output of the electric motor and a drive connectionto the electric motor.